The Court of Criminal Appeal has declared that a Co Meath mans conviction for killing his 19-year-old neighbour over four decades ago was a miscarriage of justice.

In 2010 Martin Conmey (63) was acquitted of the manslaughter of Una Lynskey, 38 years after he was jailed for three years for the offence.

This morning the appeal court comprised of Mr Justice Adrian Hardiman sitting with Mr Justice Brian McGovern said the conviction of Mr COnmey amounted to a miscarriage of justice.

Mr Conmey, represented by Hugh Hartnett SC, embraced friends and family following the ruling.

After stepping off a bus from Dublin, civil servant Una Lynskey disappeared less than half-a-mile from her home on Porterstown Lane in Ratoath, Co Meath on October 12th, 1971.

Her body was discovered two months later near Tibradden in the Dublin Mountains in an advanced state of decomposition. The cause of her death has never been determined.

Mr Conmey and his friend Dick Donnelly were convicted of Ms Lynskey’s manslaughter in July 1972. A third man, Martin Kerrigan, who was also suspected of having been involved in Ms Lynskey’s death, was abducted by and killed by Una Lynskey’s brothers Sean and James Lynskey and her cousin John Gaughan nine days after her body was discovered.

Mr Donnelly won his appeal against his conviction in 1973 but Mr Conmey’s conviction was upheld and he served three years in jail.

In November 2010 the Court of Criminal Appeal overturned this conviction after finding that early statements taken from witnesses Martin Madden and Sean Reilly - which tended to favour Mr Conmey – were not disclosed to the defence and were “radically inconsistent” with later statements of the same witnesses and evidence given at the trial.

The court heard that the statements in evidence at the trial placed Mr Conmey and Mr Donnelly on Porterstown lane during the crucial fifteen minute period in which Una Lynskey disappeared, having stepped off her bus at 6:55pm and embarked upon the short walk to her home.

Arising out of the 2010 decision Mr Conmey sought a declaration that his conviction was a miscarriage of justice.

In its ruling the CCA said Mr Conmey was concvicted on the basis he was involved in a joint enterprise with others.

The CCA said there was no incriminating evidence that Mr Conmey was involved in a joint enterprise.

This was because three original statements of other parties were suppressed by a person unknown, but connected with the prosecution.

On this narrow basis the CCA found there had been a miscarriage of justice.

Mr Conmey lawyers will now lodge an application for compensation as a result of the CCAs finding he was a victim of a miscarriage of justice.